TiO2光催化氧化技术在废水处理中的应用

介绍TiO2光催化氧化反应机理，TiO2光催化氧化技术及其在处理染料废水、农药废水、含酚废水、表面活性剂废水、制药废水、含油废水、垃圾渗滤液中降解难降解有机污染物的应用，并对其目前存在的问题和研究方向进行了简单的阐述。     

TiO_2光催化氧化处理废水的研究概况

TiO2光催化氧化法降解废水是目前废水处理方面的热点,为彻底解决废水处理问题提供了新的手段。综述了TiO2光催化氧化降解废水的反应机理、影响因素及提高光催化效率的途径。同时,指出了光催化降解废水技术需要进一步解决的问题。     

纳米二氧化钛在水处理中的研究进展

介绍了纳米TiO2制备方法及光催化氧化还原机理,概述了纳米TiO2光催化技术在降解农药废水、含油废水、染料废水、造纸废水及自来水处理中的应用,提出了纳米TiO2在水处理应用中存在的问题及解决措施,并对TiO2光催化材料在水处理中的发展趋势进行了展望。     

硫酸处理对微弧氧化TiO2膜光催化性能的影响

采用微弧氧化技术在钛网上直接制备TiO2膜,利用硫酸浸渍方法对该膜表面进行修饰,以酸性大红染料模拟废水来评价TiO2膜光催化降解水中有机污染物的能力。并对微弧氧化膜表面形貌和成分进行了分析。结果表明:由于膜表面钠的沉积,微弧氧化TiO2膜的光催化性能较差;硫酸浸渍可以减少微弧氧化TiO2膜表面钠的含量,改善膜的光催化性能,对酸性大红染料废水光催化120 min降解率由15%提高到31%。     

TiO_2-过渡金属光催化降解有机废水

纳米TiO2掺杂过渡金属离子,能有效提高其光催化活性和反应效率,在处理有机废水等方面具有广阔的应用前景。综述了纳米TiO2的光催化氧化降解机理,纳米TiO2掺杂过渡金属离子的制备方法,掺杂不同金属离子对TiO2光催化性能的影响以及在多种有机废水降解方面的应用等。     

二氧化钛光催化降解废水中污染物的研究进展

介绍了TiO2光催化氧化法降解废水中污染物的作用机理。根据近年来的研究成果,对TiO2纳米粉体和TiO2薄膜的研制方法进行了归纳。分别介绍了悬浮式光催化反应器和固定式光催化反应器,讨论了它们各自的优点和缺陷。     

纳米TiO2的光催化活性及其在废水处理中的应用进展

综述了纳米TiO2光催化降解废水中有机污染物的机理,对影响二氧化钛光催化活性的各种因素,催化剂的形态,其他物质的掺杂、负载,溶液的pH值、光源与光照强度等进行了讨论,阐述了TiO2光催化氧化在水处理中的应用进展.展望了纳米TiO2在降解废水处理中的应用前景,提出了研究发展方向.     

TiO_2/PbO_2复合膜光催化氧化降解染料废水

提出了一种TiO2/PbO2复合膜圆形光催化氧化反应器,研究了该反应器对经生化处理后的染料废水进行降解的过程.研究表明:光催化氧化的最佳条件是锌片镀TiO2/PbO2复合膜、pH=8.0、H2O2质量浓度为400 mg/L.并对其他氧化剂对该过程的影响进行了探讨.有机废水通过该反应器进行处理后,其COD降为48.4 mg/L.能使有机污染物全部降解为小分子无机物,废水达到国家一级排放标准.     

石英表面自组装二氧化钛光催化材料

用γ-巯丙基三甲氧基硅烷对石英进行干法改性，用氧化剂将巯基氧化为磺酸基，通过静电自组装二氧化钛制备石英表面自组装二氧化钛光催化材料。用制备的光催化材料处理含偶氮染料废水4h后，结果表明100℃焙烧得到的石英表面自组装二氧化钛光催化材料对偶氮染料废水的脱色率达到99.02％。其对偶氮染料有一定的吸附作用，但主要为降解作用。     

纳米二氧化钛的光催化性能及其在有机污染物降解中的应用

纳米TiO2 具有光催化性能 ,利用太阳光能将有机污染物矿化为CO2 和H2 O。从TiO2 的光催化降解机理入手 ,讨论了影响纳米TiO2 光催化性能的因素及提高光催化性能的方法 ,列举了纳米TiO2 光催化降解处理染料废水、农药废水、含有表面活性剂的废水以及含油废水的应用。最后提出目前存在的一些问题及其解决途径     

电-生物耦合技术对偶氮染料废水处理的研究进展

偶氮染料广泛应用于纺织印染等行业,产生的染料废水严重污染环境,降解处理染料废水成为了难题。本文对电-生物耦合技术的国内外研究现状、技术原理以及该技术对偶氮染料废水处理的最新研究进展进行了综述,并提出目前电-生物耦合技术在偶氮染料废水处理领域存在的问题,针对其问题对该技术的发展进行了展望。     

偶氮染料在气-液-固循环浆态光催化反应器中的降解脱氮

偶氮染料废水是一种集中量大的重要污染物,其中的偶氮键可被环境微生物降解生成具有毒性的芳香胺类化合物。本文从光量子效率、脱氮速率、脱氮能耗等方面,对比研究了一种新设计的气-液-固循环浆态光催化反应器和环隙式光催化反应器对偶氮染料降解脱氮的性能。结果表明,由于空气的引入,使气-液-固循环浆态光催化反应器的量子收率有一定程度下降,同时造成单位数量级脱氮能耗也有一定增大,但偶氮染料脱氮速率比在环隙式反应器中的情况有大幅度提高,表明气-液-固循环浆态反应器在偶氮染料废水光催化降解脱氮方面具有较大应用前景。     

处理偶氮类染料废水的研究现状及其进展

随着偶氮类染料的广泛应用，人们把目光都集中在染料废水的处理上。文章分析研究了处理偶氮类染料废水的各种方法，总结了当今处理偶氮类染料废水的工艺，并将各种方法进行比较，力求找出更加简单经济、实用高效的处理偶氮类染料废水的方法，为项目后续工作的研究奠定基础。     

Photostability of Anthraquinone and Azo Dyes in N-Ethylacetamide (Nylon Model)

Measurements of the quantum yields of photodegradation of anthraquinone and azo dyes in N-ethylacetamide (nylon model) and triplet sensitisation of dye fading showed that the photochemical reactions are initiated by an upper excited n-π* triplet state. The primary photochemical reaction with both anthraquinone and azo dyes involves hydrogen abstraction from the amide so/vent. In some cases oxygen retards dye fading by reoxidation of the reduced structures. In other cases oxygen accelerates the photochemical reaction via free-radical initiated oxidation reactions. The quantum yields of dye fading are strongly wavelength dependent. On exposure to a simulated sunlight spectrum photodegradation is mostly caused by radiation in the region 300–400 nm. While unsubstituted anthraquinone is very photoreactive, amino-substituted anthraquinones are much more photostable in N-ethylacetam/de. Photostability of mono- and di-substituted anthraquinone derivatives increases with the electron-donating power of substituent groups. Azo dyes with increased conjugation such as diazo and naphthazo structures are more photostable than simple azobenzene derivatives. Certain electron-withdrawing substituents, which do not affect dye colour, improve the ‘oxidative’ photostability of both anthraquinone and azo dyes. A cobalt premetallised azo dye (C.I. Acid Red 182) is very photostable in N-ethylacetamide, showing the effect of metal chelates on photostability. The low values of quantum yields for the dye solutions are comparable with those of acid and disperse dyes in nylon films, indicating that N-ethylacetamide is a suitable nylon model for mechanistic studies of dye fading.     

Sonochemical destruction of textile dyestuff in wasted dyebaths

Ultrasonic degradation at 300 kHz of basic azo and reactive anthraquinone dyes was investigated in dyebath wastewater at acidic and near-acidic pH. For all conditions, it was found that colour decay was exponential, levelling off at a non-zero plateau and slowing down with increased acidity. It was also found that the bleaching rate of a dyebath was more sensitive to the dye structure than to the dyebath matrix. The rate of azo dye bleaching was slower than that of anthraquinone dyes at both test pH levels regardless of the unfavourable conditions in the latter dyebath against oxidation by hydroxyl radicals. The addition of hydrogen peroxide to the dyebaths rendered a slight enhancement in the degree of colour decay and a significant increase in the overall degradation of the dyestuff.     

Photodegradation of azo‐dyes in aqueous solution by polyacrylonitrile nanofiber mat‐supported metalloporphyrins

Electrospinning has been employed to fabricate uniform polyacrylonitrile and polyacrylonitrile copolymer nanofiber mats supporting metalloporphyrins (MTPP; M: Zn(II), Cu(II), Ni(II), Co(II), Fe(III) and Pd(II); TPP: meso‐tetraphenylporphyrin). The nanofiber mat‐supported metalloporphyrins are shown as efficient photocatalysts for the degradation of various azo‐dyes in aqueous solutions under visible light irradiation. The effect of transition metals on azo‐dye photodegradation has been examined. The nanofiber mat‐supported copper–porphyrin and iron–porphyrin complexes are among the most effective photocatalysts for azo‐dye degradation. Immobilization of the metalloporphyrins onto the nanofiber mats greatly facilitates the recovery and reuse of the expensive and toxic photocatalysts. Most interestingly, there are no significant degradations of the photocatalytic activities of the recycled photocatalysts. © 2012 Society of Chemical Industry     

Integration of photocatalysis and membrane distillation for removal of mono- and poly-azo dyes from water

The paper reports investigations on the application of anatase-phase TiO₂ for the removal of azo dyes in a hybrid system coupling photocatalysis with direct contact membrane distillation (DCMD, MD). The process was conducted in a laboratory-scale installation equipped with a PP capillary module. The influence of reaction temperature and initial concentration of azo dyes on the effectiveness of their photodegradation was especially investigated. Two mono-azo dyes: Acid Red 18 (AR18) and Acid Yellow 36 (AY36) and one poly-azo dye, Direct Green 99 (DG99) were applied as model compounds. The increase of the reaction temperature from 313 to 333 K resulted in an improvement of the efficiency of photodecomposition of the dyes, as was found on the basis of changes of their masses in the feed solution. The comparison of the results obtained during photocatalysis alone and hybrid photocatalysis-MD process revealed that the reduction of feed volume in MD did not affect the photodegradation rate of the azo dyes. An improvement of the effectiveness of the degradation of dyes was obtained by an application of solutions with lower initial concentration (10 instead of 30 mg/dm³). Regardless of the process parameters applied, the product (distillate) was almost pure water with conductivity lower than 0.3 mS/m and pH above 5.2.     

偶氮类染料废水处理技术的研究进展

染料的使用伴随着大量有机废水的产生,不但对环境保护带来巨大的威胁还危及人类的身体健康。在印染工艺中,偶氮类染料是应用最广泛的一类合成染料。综述了国内外偶氮类染料废水处理技术的研究现状,对物理法、化学法、生物法在偶氮类染料废水处理中的应用进行了简要介绍,并阐述了各种方法的作用机理。根据绿色化学的要求对现有处理技术进行改进,以提高偶氮类染料废水的处理效率使其达标排放。     

生物强化-氧化还原介体联合强化高盐偶氮染料废水生物脱色的研究

偶氮染料是一类应用最为广泛的染料,其处理过程受到人们的关注。在偶氮染料的生物处理过程中,脱色是至关重要的步骤,也是限速步骤。本研究利用耐盐偶氮还原菌Exiguobacterium sp.TL及氧化还原介体——蒽醌联合强化活性污泥处理高盐活性艳红X-3B废水,分别考察了蒽醌对活性污泥和强化菌脱色效率的影响,以及生物强化作用对活性污泥驯化的影响,结果显示,耐盐菌生物强化可提高活性污泥驯化的速率,而蒽醌对强化菌的脱色效率也有加速作用,但对活性污泥产生了抑制。在此基础上,建立了先生物强化,再投加蒽醌的分步联合强化工艺,模拟工艺启动时间缩短了约3 d,脱色效率最高可达约1 000 mg/（g.d）。     

液电效应催化臭氧处理4种偶氮染料废水的研究

使用自行设计构建的高压脉冲放电催化臭氧氧化装置，首先以K-2BP为模型化合物，确定了最优操作条件，并在此操作条件下对酸性黄17、酸性黄Bis和酸性黄11、4种结构相似的模拟染料废水进行实验研究，结果表明：4种染料的脱色率和COD去除率，与吸电子基团磺酸基和氯取代基相对于偶氮键的位置和数量有关。